The invention concerns devices for measuring the radiation from antennae, and in particular devices for evaluating the radiation diagram of an antenna.
We are already familiar with anechoic chambers, in the form of an enclosure capable of receiving not only the antenna to be examined, but also an operator who positions, or even holds the antenna during the tests.
Such anechoic chambers can contain a series of analysis antennae, positioned on a circle surrounding the antenna to be examined. The output signals from this series of test antennae provide the data used to draw a radiation diagram in the plane on which this circle is located at any given moment.
By effecting a relative rotation between the antenna to be examined and the analysis antennae, one can therefore produce a series of radiation diagrams, where all of these are used to create a picture of the overall radiation pattern in three dimensions diagrams.
We are also already familiar with such devices for measuring the radiation from the mobile telephones, in which the user of the telephone is himself placed inside the circle formed by the different analysis antennae.
Nowadays, the characterisation and/or the monitoring of an antenna or of any other electromagnetic object, whether transmitter or receiver, are currently outsourced to the possessor of an anechoic chamber equipped as described who, in return, provides the designer of the antenna with the requested radiation diagram.
The design of an antenna can involve multiple structural changes in the course of its design, according to the radiation that is measured around it in an anechoic test chamber.
It appears nowadays that people are requiring faster and faster feedback from these analysis. In particular in the context of an antenna design process, the analyses for successive different versions of the antenna have to be supplied with increasing rapidity.